Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
dinh tri » chinh tri
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cac xuc » cam xuc, cac nuoc, chat xuc
xuc van » duc van, luc van, vuc van
cuc tre » duc tre, cua tre, cuu tre
co hai » co dai, co hoi, so hai
o hai » so hai, o lai, _ hai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang ((o hai) or (co hai)). hieu vien cac xuc van ((dinh thi) OR (dinh tri)) cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((o hai) OR (co hai)). hieu vien cac xuc van ((dinh thi) OR (dinh tri)) cuc tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((o hai) or (co hai)). hieu vien cac xuc van ((dinh thi) OR (dinh tri)) cuc tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hai) or (co hai)). hieu vien cac xuc van ((dinh thi) OR (dinh tri)) cuc tre*.